Ethylene sulfide polymers



United States Patent 3,365,431 ETHYLENE SULFIDE POLYMERS Riad H. Gobran,Levittown, and Stephen W. Osborn,

Yardley, Pm, assignors to Thiolrol Chemical Corporation, Bristol, Pa.

N0 Drawing. Continuation-impart of applications Ser. No. 162,555, Dec.27, 1961; Ser. No. 168,836, Jan. 25, 1962; Ser. No. 274,366, Apr. 22,1963; Ser. No. 352,348, Mar. 16, 1964; and Ser. No. 357,300, Apr. 3,1964. This application Dec. 3, 1965, Ser. No. 511,341

26 Claims. (Cl. 26079.'7)

ABSTRACT OF THE DISCLOSURE Solid, high molecular Weight moldablepolymers having a major proportion by weight of recurring units derivedfrom ethylene sulfide, and a positive melt index value at 215 C. belowabout 1.5 grams per minute.

This application is a continuationin-part of our prior applications Ser.Nos. 162,555 filed Dec. 27, 1961, now abandoned; 274,866 filed Apr. 22,1963, now abandoned; 168,836 filed Jan. 25, 1962, now abandoned; 352,348filed Mar. 16, 1964 and 357,300 filed Apr. 3, 1964.

The present invention relates to solid polymers of ethylene sulfide, andmore particularly, to novel, relatively high molecular weight, moldableethylene sulfide polymers. The polymers of the invention comprisehomopolymers of ethylene sulfide, as well as copolymers or interpolymerslargely composed of ethylene sulfide units but also containing minoramounts of units derived from other monomers copolymerizable withethylene sulfide such as other vicinal episulfide monomers. The presentproducts are solid, high molecular weight, thermoplastic polymers havingrelatively high melting points. As pointed out in detailed below, theyare further characterized by a relatively low melt index, Le, a positivemelt index value at 215 C. below about 1.5. They are capable of beingmolded at elevated temperatures to produce continuous plastic media invarious configurations depending upon the forming process used. Hencethey may be employed to produce a Wide variety of molded articles.

For example, the present polymers can be molded to form pipe, tubing,containers, film, strips and funicular structures such as filaments,threads and rods, using any of the conventional molding procedures knownto those in the art such as extrusion, compression or injection moldingprocedures. The articles thus formed have exceptional utility atelevated temperatures and particularly in the presence of solvents suchas water, benzene, heptane, hexane, methanol, ethanol, acetone,acetonitrile, carbon tetrachloride, chloroform, dimethylformamide,dioxane, tetrahydrofuran, carbon disulfide, chlorobenzene,o-chlorobenzene, p-chlorotoluene and methylene chloride.

Certain of the properties of the present polymers vary as a function ofthe proportion of ethylene sulfide units they contain. Considering firstthe properties of the ethylene sulfide homopolymers, these polymers arehighly crystalline materials as determined by X-ray diffraction. Theyhave melting points of the order of 200 to 215 C. as determinedmicroscopically using a Kofler hot stage at a heating rate of 3 C. perminute. They are also characterized by excellent solvent and chemicalresistance. In molded :form they have high heat distortion temperatures,low Water absorption properties, extremely low deformation under loadand excellent dimensional stability. More particularly, ethylene sulfidehomopolymers can be prepared as disclosed herein having heat distortiontemperatures (ASTMD648) of the order of 300 to 320 F. using a 264 p.s.i.load, water absorption values (ASTM-D570) below 0.10% and deformationunder load values (ASTM-D261) of the order of 0.10 to 0.30%.

For the most part the above-described physical properties of thehomopolymers are modified to some extent in the case of the copolymersor interpolymers. For example, as the proportion of comono-rner that iscopolymerized with the ethylene sulfide monomer increases, the meltingpoint and crystallinity of the resulting products tend to decrease.However, by the method disclosed herein copolymers containing up to 30%by weight of units derived from the copolymerizable monomer can beprepared which have melt indices at 215 C. below about 1.5 grams perminute and consequently have satisfactory molding properties. Moreover,copolymers containing up to say a few percent of oopolymerizable monomerare, like the ethylene sulfide homopolymers, predominately crystalline.Hence those ethylene sulfide polymers of the invention that arepredominately crystalline may be characterized as essentiallyhomopolymeric poly(ethyl ene sulfide).

The ethylene sulfide polymers of the invention may be prepared bypolymerizing ethylene sulfide either alone, or in conjunction with aminor amount of one 'or more other monomers which are copolymerizabletherewith, in the presence of a catalyst such as a reaction product ofdiethyl zinc and water or diethyl zinc and hydrogen sulfide. Monomerswhich have been found to be readily polymerizable with ethylene sulfideusing such catalysts are other vicinal episulfide monomers, preferablythose containing 3 to 10 carbon atoms. Examples of such comonomers arealkylene sulfides such as propylene, 1,2- rbutylene, 2,3-butylene,isobutylene, and cyclohexene sul fides; styrene sulfide;vinylcyclohexane, vinylcyclohexene, paramethylstyrene and butadieneepisulfides; Z-rbenzylthiirane; 1,2 epoxy 3,4-epithiobutane; andallylthioglycidyl ether. As indicated above, in order to obtain moldablepolymers having the desired properties, the polymer should contain atleast 70% by weight of units formed from ethylene sulfide, which units,in the polymeric backbone, will have the structure CH CH -S. The precisestructure of the present polymers is not known, that is to say, theextent, if any, to which the polymer molecules may be branched chains isnot known, nor is it known whether the component units are distributedin a random or successive pattern in the polymer backbone.

As indicated above, the polymers of the present invention can beconveniently characterized in terms of their melt indices. The numericalvalues of melt index disclosed herein were obtained with a capillaryflow plastorneter of the type sold by F. F. Slocomb Corporation ofWilmington, Del. The test procedure used confronted generally to ASTMmethod D1238-57T. In determining the melt indices, the plugged reservoirof the test instrument Was preheated to and maintained at 215 C. :2" C.and then charged with 4 to 6 grams of polymer within a 2-minuteinterval. A S-kg. weight was then placed atop the charge by means of aram and left there for 2.00 minutes. The S-kg. weight was then replacedwith a 2160-gram weight. After an additional 0.25 minme the plug wasremoved from the flow orifice of the reserv-oir, and the flow of polymerthrough the orifice was measured. The amounts of polymer which flowedthrough the orifice during each l-minute interval were separatelycollected and weighed to the nearest milligram. The melt index valuesgiven herein are averages of the weights of the l-minute samplescollected over the first 5 minutes of the test. Thus if a total of 3.5grams of polymer flowed through the orifice during the first fiveminutes of the test, the melt index of the polymer, as defined herein,would be 0.7 gram/minute.

Comparisons of the weights of different samples of a given type ofpolymer extruded within a given time interval by this procedure providean indication of the relative molecular weights of the differentsamples, the lower flow Weights per unit time interval indicating highermolecular weight materials. It has been found that ethylene sulfidepolymers which have a melt index at 215 C. of less than about 1.5grams/minute are readily moldable using injection, extrusion or othermolding procedures. The term positive melt index value is used herein toindicate that the melt index is greater than zero.

Although ethylene sulfide polymers having a melt index at 215 C. of upto 1.5 grams/minute can be injection molded, it is preferable from thestandpoint of ease of processibility to use, in injection moldingprocedures, a material having a melt index in the range 0.7 to 1.5grams/minute. For extrusion molding procedures it is preferable to useethylene sulfide polymers which have a melt index at 215 C. of no morethan about 0.7 gram/ minute.

The stability of the ethylene sulfide polymers of the present invention,under the rigorous molding temperatures commonly employed when moldingsuch relatively high melting materials, can be improved by admixing withthe polymers, as a stabilizer, about 0.5 to 2.5% by weight of thepolymer of one or more amines such as octadecyl amine, branchedoctadecyldimethylamine and p-aminodiphenylamine, and/or one or moreamide stabilizers such as nylon, acrylamide polymer and fatty acidpolyamides. The stabilizer can be incorporated in the polymer bymechanically mixing it with the polymer in powder form. Stabilization ofethylene sulfide polymers with such amines and amides, among otherstabilizers, is disclosed in application Ser. No. 267,605 filed Mar. 25,1963; application Ser. No. 267,604 filed Mar. 25, 1963; application Ser.No. 312,847 filed Oct. 1, 1963; application Ser. No. 323,074 filed Nov.12, 1963; application Ser. No. 349,799 filed Mar. 6, 1964 andapplication Ser. No. 477,- 288 filed Aug. 4, 1965. Polymers havingdifferent melt indices as defined herein can be mixed to produce blendshaving intermediate melt indices.

Articles molded from the present polymers at elevated temperatures andpressures exhibit good impact resistance and good machining properties,as well as other improved properties previously mentioned and consideredin more detail in the examples given below. As indicated above, thepolymers containing a high proportion of ethylene sulfide units arehighly crystalline and the crystallinity of the polymer varies ininverse relation to the amount of cornonomer units therein.

The polymers of the invention can be formed into continuous flexiblefilms and molded by compression, injection or extrusion moldingprocesses to a Wide variety of articles having novel combinations ofphysical and chemical properties. The ethylene sulfide homopolymers inparticular are substantially completely insoluble in a wide variety ofsolvents including water, benzene, heptane, hexane, methanol, ethanol,acetone, acetonitrile, carbon tetrachloride, chloroform,dimethylformamide, dioxane, tetrahydrofurane, carbon disulfide,chlorobenzene, o-dichlorobenzene, p-chlorotoluene, and methylenedichloride. The term insoluble as used in the preceding sentencesignifies that when the polymer was shaken in the solvent at roomtemperature for 24 hours, there was no appreciable change in therefractive index of the solvent, and the polymer was recovered byfiltration at the test temperature without loss in Weight. It has beenfurther found that ethylene sulfide homopolymers made by methodsdisclosed herein are also resistant to such solvents at elevatedtemperatures. For example, such homopolymers have been found to besubstantially insoluble when heated in o-dichlorobenzene at 180 C. for aperiod of 4 hours.

The preferred catalyst for use in preparing the present polymers is areaction product of diethyl zinc and either water or hydrogen sulfide.The molar ratio of diethyl zinc to water or hydrogen sulfide may varyfrom about 1:3 to 3:1. The diethyl zinc-Water catalyst may be preparedby reacting the diethyl zinc and water in an inert hydrocarbon solvent,e.g., benzene or hexane, at a temperature of 0 to 85 C., preferably 20to 50 C. The molar ratio of diethyl zinc to water is preferablyapproximately 1:1, although it may vary over the range indicated above.To insure optimum catalyst activity and the attainment of the highestmolecular weights, the catalyst should be used within a period of notmore than 48 hours after it is prepared and preferably as soon aspossible after it is prepared. In most cases it will be found desirableto prepare the catalyst in the polymerization reaction vessel just priorto or coincident with the initiation of the polymerization reaction.

It has been found important that in cases where the highest molecularweights are desired the preparation of the catalyst and also thepolymerization reaction be carried out in an environment substantiallyfree from elemental oxygen and free from water other than that used inpreparing the catalyst. Thus catalyst preparation and polymerization aredesirably carried out in an atmosphere of inert gas such as nitrogen,helium, or argon containing less than about 20 parts per million ofoxygen. Commercially available grades of diethyl zinc have been foundsuitable for use in the present invention. The water with which thediethyl zinc is reacted should be distilled Water, preferablydeoxygenated by boiling, followed by cooling under a pure nitrogenatmosphere. The hydrocarbon solvent used in preparation of the catalystshould desirably be either dried over sodium or freshly distilled.

The diethyl zinc-hydrogen sulfide catalyst can be prepared in the samegeneral manner as indicated above for the diethyl zinc-water catalyst.The molar ratio of H 5 to diethyl zinc employed may vary from about0.5:1 to 12:1 with the preferred ratio being about 1:1. The diethyl zincmay be dissolved in the solvent and H 5 gas bubbled through the solutionor alternatively, a standard, saturated solution of H S in hydrocarbonsolvent can be mixed in predetermined proportions with a standardsolution of diethyl zinc in a hydrocarbon solvent. The diethyl zinc-H 8catalyst, like the diethyl zinc-Water catalyst, should be freshlyprepared in a substantially oxygen-free environment and, if the highestmolecular weights are desired, in an anhydrous environment.

Details of the polymerization process are given in the specific examplesset forth below. In general, the polymerization process is executed bybringing the monomeric ethylene sulfide, or mixture of ethylene sulfideand other copolymerizable cornonomer into contact with the catalystprepared in the general manner rescribed above. The catalyst isdesirably used to the extent of about 0.05% to 3% based on the weight ofthe monomer charge being polymerized. The preferred amount of diethylzinc-water catalyst is about 1% to 2% and the preferred amount of thediethyl zinc-H S catalyst is about 0.5%. The polymerization reaction canbe carried out at temperatures of 20 C. to C. over periods of a fewminutes to 48 hours. Relatively high molecular weight products areobtained when the reaction system is maintained anhydrous except for thequantity of water required to form the diethyl zinc-water catalyst asdescribed above.

The polymerization reaction may be conducted without using a solvent, orany of various inert organic solvents can be used such as aromatichydrocarbons, e.g., benzene, toluene, or xylene; aliphatic hydrocarbons,e.g., isopentane, n-hexane, or octane; or chlorinated hydrocarbons,e.g., carbon tetrachloride, methylene chloride, or ethylene chloride.The reaction mixture may be agitated to facilitate the reaction. Thepressure at which the reaction is carried out does not appear to beparticularly critical. Thus the reaction may be carried out atatmospheric pressure or under autogenous or higher pressures. In anycase the reaction mixture should desirably be kept oxygenfree by the useof an atmosphere of purified inert gas.

In order to point out more fully the nature of the present invention,the following specific examples are given of illustrative methods ofmaking the present products.

indicate the number of tests run, the values given in the table beingaverages for the indicated number of tests.

TABLE I Example 1 A solution of diethyl zinc-water catalyst was preparedCylindertemp, Nozzle temp., Mold temp Annealing prior to use in thepolymerization described below with powdure 252.2 millirnoles/ 227millimoles of diethyl zinc/H O I" U 1 1 A mixed under a blanket ofnitrogen gas in 2270 ml. of 53;? 53 2 A dried benzene. 415 435 g. A 130gal. reactor was sequentially charged with 170 2;? fig B lbs. (23.2gal.) of dried benzene, 0.832 mole (50 lbs., 415 85 302 B 5.8 gal.) ofdried ethylene sulfide monomer, and the total TABLE II Izod ImpactTensile Elongation, Flexural Flexural strength, strength, percentstrength, modulus, ft.lb./in., p.s.i., ASIM D-638 p.s.i., p.s.i., ASTMD-256 ASTM D-638 ASTM D-790 ASTM 13-790 1. 02 6,586 (5) 3 (5) 13,543 (5)315, 440 (5) 1.03 6, 543 (3) 4(3) 13,39s(5) 3 ,800(5) 0. 09 4,415 (5)3(5) 11,390 (5) 400,880 (5) 1. 55 6,731 (5) 3 (5) 13, 551 (5) 5, 825(5) 1. 13 5, 920 (3) 4 (3) 13,154 (4) 332, 5 75 (4) 0. 96 5,896 (5) 2(5) 11, 35s (5) 388, 3 e0 (5) amount of catalyst solution that waspreviously prepared Example 2 the same day, as described above, allunder a blanket of nitrogen gas with agitation. The reactor was sealed,and the temperature of the reactant mixture was raised to about 176 F.and held thereat for 2 hours. The contents were then cooled, the reactorunsealed, and the wet polymer product dried first by centrifuging tospin off the liquid portions, then through vacuum drying at elevatedtemperatures not exceeding 118 F. The dried powdery white crystallinepolymer product obtained had a melting point range of 208 to 214 C. andmelt index average flow value for the first five minutes of flow at 215C. of 0.12 g./min.

To demonstrate the insolubility of the homopolyrners of the presentinvention 2.5 grams of the polymer prepared above was added to 50 gramsof o-dichlorobenzene. The solvent had a refractive index of 1.5492 at 25C. before the test, based on three readings of 1.5492, 1.5491 and1.5492. The mixture of polymer and solvent were periodically agitatedand held at a temperature of 180 C. for 4 hours and the undissolvedpolymer was then filtered from the solvent at 180 C. using a sinteredglass filter. The solvent was then cooled to room temperature and it hada refractive index at 25 C. of 1.5490, based on four readings of 1.5489,1.5490, 1.5490 and 1.5491. A control sample of solvent was also held at180 C. for four hours, without polymer therein, and after being cooledto room temperature, it had a refractive index at 25 C. of 1.5492, basedon three readings of 1.5491, 1.5492 and 1.5492.

Six samples of polymer made according to the procedure given above wereinjection molded into /2 x 4;" x 3" bars using conventional injectionmolding equipment (Unex Jet Plastic Molder, Hinchman ManufacturingCompany, Inc., Roselle, NJ). The molding and annealing conditions aregiven in Table I below. Molding was effected at three differenttemperatures, and two dilferent annealing procedures, A and B, wereused. In procedure A the molded article was water-cooled at tap watertemperatures, whereas in procedure B the molded article was maintainedat 180 C. for 7 minutes, followed by gradual atmospheric cooling to roomtemperature.

After annealing, the molded materials were tested for Izod impactstrength, tensile strength, elongation, fiexural strength and fiexuralmodulus properties. The results are given in Table II below, wherein thestandard ASTM tests used are identified. In Table II the numbers inparentheses A 10 gal. reactor was charged with 33.8 lbs. (4.6 gal.) ofdried benzene under an atmosphere of nitrogen gas. To this was added0.05 mole (0.901 ml.) of water with agitation. After 10 minutes ofstirring, 49.5 ml. of a benzene solution containing 0.05 mole of diethylzinc was added. Stirring was continued for 60 minutes, at the end ofwhich time 37.6 moles (0.576 gal.) of ethylene sulfide monomer was addedand the reactor was sealed. The reaction mixture was then held at 176 F.for 2 hours, then cooled and vented to a nitrogen atmosphere. The liquidportion of the product slurry was spun off in a centrifuge, and thesolids obtained thereby were dried under vacuum at 120 F. for 8 hours.The vacuum was broken with nitrogen gas, and the dried polymer productwas then cooled and used for physical property testing. It had a meltingpoint of 204-206 C. and a melt index average flow of 0.15 g./min. duringthe first five minutes at 215 C.

Example 3 A gal. reactor was charged with 466.0 lbs. of dried benzeneunder an atmosphere of nitrogen gas. To this was added 0.953 mole (16.18ml.) of water with agitation. After 10 minutes of stirring, 800.8 ml. ofa benzene solution containing 0.953 mole of diethyl zinc was added.Stirring was continued for 30 minutes, at the end of which time 287moles (38 lbs., 4.4 gal.) of dried ethylene sulfide monomer was added.Another 50 lbs. of dried benzene was added with agitation to give atotal solvent charge of 70.4 gal., and the reactor was sealed. Thereaction mixture was then maintained at 176 F. for 2 hrs., then cooledand vented to a nitrogen atmosphere. The product slurry was thenfiltered, and the solid crystalline product obtained thereby was driedunder vacuum for 4 hours at an elevated temperature not exceeding 176 F.The vacuum was broken with nitrogen gas, and the dried polymer was thencooled and used for physical property testing. It had a melt indexaverage flow of 0.16 g./min. during the first five minutes at 215 C.

Example 4 A 100 gal. reactor was charged with 254.2 lbs. (34.7 gal.) ofdried benzene under an atmosphere of nitrogen gas. To this was added0.378 mole (6.815 ml.) of water with agitation. After 10 minutes ofstirring, 564.1 ml. of

a benzene solution containing 0.378 mole of diethyl zinc was added.Stirring was continued for 60 minutes, at the end of which time 564.5moles (75 lbs., 8.67 gal.) of dried ethylene sulfide monomer was addedand the reactor was sealed. The reaction mixture was then held at 176 F.for 2 hours, then cooled and vented to a nitrogen atmosphere. The liquidportion of the product slurry was spun off in a centrifuge, and thesolids obtained thereby were dried under vacuum for 4 hours at 120 F.The vacuum was broken with nitrogen gas, and the dried polymer productwas then cooled and used for physical property testing. It had a meltingpoint of 204.5207 C. and a melt index average flow of 0.11 g./min.during the first five minutes at 215 C.

Example 5 A dry 30 02. glass polymerization vessel was sequentiallycharged by mixing under a blanket of nitrogen gas 400 ml. of driedbenzene, approximately 100 g. (100 ml.) of dried ethylene sulfidemonomer, 0.0011 mole (0.02 ml.) of water and 0.58 ml. of a benzenesolution containing 0.0011 mole of diethyl zinc. The vessel was sealedand the contents raised to and maintained at 80 C. for 2 hours withagitation. The wet white polymer thus obtained was dried at 210 mm. Hgvacuum in an oven at 6070 C. for about 24 hours to produce 97.6 g. of adried white powdery crystalline polymer product having a melting pointof 208 C., and a melt index average flow at 215 C. during the first fiveminutes of flow of 0.11 g./min,

Example 6 In similar manner to Example 5, excepting that in the sequenceof charge of reactants the benzene solution containing diethyl zinc wascharged to the polymerization vessel prior to charge of water, 97.9 g.of a dried white powdery crystalline polymer product was obtained whichhad a melting range of 206 to 208 C. and a melt index average flow at215 C. during the first five minutes of flow of 0.21 g./min.

Example 7 A dried white powdery crystalline polymer product was preparedaccording to the method of Example 6, the only change being that 0.00083mole (0.015 ml.) of water was used rather than 0.0011 mole (0.02 ml.).The product had a melting point of 207-208 C. and a melt index averageflow value of 0.19 g./min. at 215 C. for the first five minutes.

Example 8 Two polymerization bombs were each charged with 200 ml. ofbenzene, 200 ml. of ethylene sulfide and ml. of a zinc diethyl/H Ocatalyst solution (prepared by reacting 11.11 millimoles of 0 free H Owith 11.11 millimoles of zinc diethyl in 100 ml. of benzene). The twobombs were then sealed and tumbled in an 80 C. water bath for 65minutes. The bombs were then removed from the bath, cooled and opened.The solvent was removed from the resulting gel like mass in a vacuumoven at 50 C./ 1 mm. Hg. A white, fluffy powdered polymer product wasthus obtained from each bomb as follows:

Bomb Grams of Polymer Percent Yield ing and testing procedures indicatedin Table III below The results of these tests are indicated in thetable.

Example 9 A 1 liter reaction flask equipped with a stirrer, nitrogeninlet and outlet tubes and a condenser was charged with 450 ml. ofheptane. The flask was then purged with carefully purified nitrogen for15 minutes, after which ml. of solvent was distilled 011 under thenitrogen atmosphere to insure an oxygen-free and anhydrous environment.The system was then cooled to 70 C. and 0.1 gram (3 drops) ofdeoxygenated distilled water and 0.7 gram (14 drops) of a benzenesolution of a commercial grade of diethyl zinc were successively addedto the heptane through the nitrogen inlet tube. Equimolar quantities ofthe diethyl zinc and water were used.

The mixture in the flask was warmed to room temperature, and a cloudyprecipitate of zinc ethoxide appeared. The mixture was again cooled to70 C. and 30.0 grams of freshly distilled ethylene sulfide was added tothe heptane solution. An exothermic reaction occurred which caused thetemperature of the system to rise 8 C. When the reaction had subsided,the system was allowed to come to room temperature and stand overnight.A heavy white flocculent precipitate formed which was collected byvacuum filtration and extracted with two 200 ml. portions of methanolfor several hours to remove residual catalyst. The resulting materialwas dried overnight in air. Residual solvent was removed by heating theproduct at about 45 to 50 C. in a vacuum oven at an absolute pressure of1 mm.

The product thus obtained comprised 18.3 grams (60% of theory) ofcrystalline polyethylene sulfide which melted sharply at 203-4 C. to aclear liquid. When cooled in a thin layer it formed a highly fiexiblefilm. The product had a sulfur content of 51.03% and was insoluble inbenzene. When subjected to an infra-red spectrographic analysis, itshowed principal absorption maxima at 710, 1128 1170, 1245, 1400 and2910 cm.-

The powdered product thus obtained was molded in the following manner. Acylindrical positive pressure mold 37.5 mm. in diameter and 10 mm. deepwas coated with a mold release (Dow-Corning Inc. DC-20) and baked in anoven at C. for thirty minutes. The mold was then charged with 10 gramsof the polyethylene sulfide powder. The piston was then introduced intothe mold and the mold assembly placed between the platens of a hydraulicmolding press. Molding was effected at a pressure of 18,000 psi. at atemperature of 365 to 385 F. for a period of thirty minutes. Thepressure was periodically removed during the molding period to permitany evolved gas to escape. The molded product was a tough plasticarticle which resisted severe impact stresses applied there- 10.

Example 10 A flask of the type referred to in Example 9 was charged with450 ml. of freshly distilled heptane and purged with nitrogen. 75 ml. ofthe heptane was distilled off under the nitrogen atmosphere.Approximately equimolar quantitles of diethyl zinc solution and waterwere added to the heptane in the flask as in Example 9.

After standing overnight at room temperature, the contents of the flaskwere heated to 5052 C. and 41.5 grams of freshly distilled ethylenesulfide (B.P. 5455 C) were added to the heptane solution. A whiteflocculent precipitate began to form within ten minutes, and its volumegradually increased. Heating of the mixture was stopped after threehours, and the system was allowed to stand at room temperature overnightwith the contents under nitrogen. Two forms of the polymer wererecovered from the flask after removing the solvent and catalyst asdescribed in Example 9. 27 grams (65% yield) of a white fluffycrystalline powder was obtained which melted at 206-207 C. to form aclear liquid. Cooling of the molten product in a thin layer yielded ahighly flexible film. Also there was removed from the stirrer 3 grams ofa tissuepaper thin film of polymer that was rubbery, semi-transparent,and melted sharply at 206 C. The total yield of product was 72%. Bothportions of polymer product were insoluble in benzene.

The cylindrical mold of Example 9, previously coated with a moldrelease, was charged with 15 grams of the flocculent ethylene sulfidepolymer produced as above. The polymer was molded at 14,000 psi. and 400F. for about 30 minutes. At ten-minute intervals the pressure wasreleased briefly and then reapplied to permit the escape of any evolvedgas. At the end of the 30-minute molding period, the mold was allowed tocool overnight. Parts of the mold came apart readily, and a slightlyyellow tablet was removed. The molded product was hard and extremelyresistant to impact.

Example 11 A clean, dry 30-ounce glass container was charged with 100ml. benzene, 0.15 ml. of deoxydized water, and 2.0 ml. of a solution ofdiethyl zinc and benzene (0.00521 moi/ml.) and the mixture was agitatedunder a nitrogen atmosphere for four to ten minutes. 50 ml. of ethylenesulfide freshly distilled from calcium hydride was then added to themixture in the container, and the container was flushed with nitrogen.Thereafter the container was capped with aluminum foil and allowed tostand at room temperature overnight. A solid white product was formedfrom which solvent was removed by heating the product under a vacuum at60 C. The resulting dried white powdery polymer had a melting point of203-205 C. The yield was 24.7 grams (49.3% of theory).

Example 12 I A thirty-ounce polymerization bottle was successivelycharged with 100 ml. of benzene and 0.15 ml. of water. The bottle wasthen flushed with nitrogen and charged with 2 ml. of a 0.00578 mol/ml.solution of zinc diethyl in benzene. The solution was alowed to stand atroom temperature until it started to yellow, which took about two hours.

A nitrogen-filled 30-ounce polymerization bottle was successivelycharged with 50 ml. of freshly distilled ethylene sulfide and 10 ml. ofthe catalyst solution as prepared above. The contents of the bottle werethoroughly shaken after which the bottle was flushed with nitrogen,capped, and allowed to stand overnight at room temperature. Polyethylenesulfide was formed which was separated and heated at 35 C. to removesolvent in a vacuum oven under 1 mm. mercury vacuum for about fourhours. A flufiy material was obtained comprising 13 grams (20% oftheory). The polymer product had a melting point of 208-212 C. Themolten product when cooled in a thin layer formed a thin flexible film.

Example 13 A l-liter resin pot was fitted with a condenser, thermometer,stirrer and nitrogen gas inlet tube. 450 ml. of hexane were charged intothe pot and 50 ml. of it were distilled off under nitrogen. The solventwas allowed to cool below 50 C. under nitrogen and 100 ml. of ethylenesulfide were pipetted into the pot. The pot and contents were thenheated on a 75 C. water bath. When the system began to reflux, 10 ml. ofa freshly prepared preformed diethyl zinc-H 8 catalyst solution wereadded thereto. The catalyst comprised the reaction product of 5.0 ml.(0.00327 mole) of H S and 0.492 ml. (0.00327 mole) of diethyl zincdissolved in 50 ml. of benzene.

A polymer of ethylene sulfide began to form as soon as the catalystsolution was added. Further 10 ml. quantities of the catalyst solutionwere added to the pot at 30- minute intervals while the system wasrefluxing at a temperature of 57-63 C. until all 50 ml. of the preformedcatalyst system had been added.

A 300 mm. Widmer column was then connected to the resin pot in place ofthe condenser and fitted with a distillation head. Unreacted ethylenesulfide was distilled off at 5559 C. at 760 mm. 88.5 cc. of the monomerwas thereby recovered. A gas chromatographic analysis showed that themonomer contained approximately 25% hexane. The hexane remaining in theresin pot was now removed by steam distillation. The remaining white,powdery product was separated from the water in the pot by filtrationand placed in a vacuum oven to dry at room temperature and 1 mm. ofmercury pressure. The yield was 48.2%. Using a Fisher Johns blockmelting point determination procedure, it was found that the polymerproduct had a melting point of 205 to 215 C. With a Kofler MicroHotstage device the melting point was 204 to 210 C. (corrected). Themelted polymers of the present example had a viscosity higher than theviscosities of the melted polymers of the preceding examples, thusindicating that the H S-diethyl zinc catalyst is capable of producinghigher molecular weight products.

Some of the polymeric material made above when molded for ten minutes at425 F. under approximately 2200 lbs. per square inch pressure yielded apaper-thin, 4- inch square flexible film.

One gram of the polyethylene sulfide produced above was added to 100 ml.of the reagent grades of each of four diflerent solvents: benzene,methylene chloride, hexane and chloroform and shaken in the solvent for24 hours at room temperature. A measurement of the refractive index ofeach of the solvents after this test showed that none of thepolyethylene sulfide had dissolved in the solvent.

Example 14 A catalyst solution was prepared under nitrogen by dissolving2 ml. of a benzene solution of diethyl zinc, containing 0.0111 mole ofdiethyl zinc, in 100 ml. of anhydrous benzene. To this solution wasadded 8.5 ml. of a solution of hydrogen sulfide in benzene containing.00555 mole of H 8. The mixture was shaken frequently for about 30minutes before use.

A steel bomb was washed, rinsed with water and then acetone, and thendried with nitrogen. 100 ml. (100.4 grams) of crude ethylene sulfide wasfiltered into the bomb through a medium sintered glass funnel. 5 ml. ofthe freshly prepared catalyst solution was pipetted into the bomb undernitrogen. The bombs cap was screwed on using 0 rings to provide a tightseal. The bomb was then placed in an C. water bath for four hours. Thebomb was then removed and cooled to room temperature with tap water andopened. A slight pressure buildup in the bomb was noticed when the bombwas opened. The product was a white, very light weight powdery polymerwhich came out of the bomb in almost one solid mass. The yield was 90.2grams or Melting point of the polymer was 206 to 210 C.

Example 15 An ethylene sulfide/propylene sulfide copolymer havingapproximately an 85/ 15 weight ratio of ethylene sulfide to propylenesulfide units was prepared as follows:

A clean 30-ounce bottle was flushed with nitrogen and successivelycharged with ml. of benzene, 0.15 ml.

(0.0083 mol) of oxygen-free water and 10.90 ml. (0.0115 mol) of a0.001055 mol/ml. solution of diethyl zinc in benzene, and the solutionwas allowed to stand at room temperature under a nitrogen atmosphereuntil it had developed a yellow color. 15 ml. (14.2 gm., 0.192 mol) ofpropylene sulfide were then added to the solution, and the system wasallowed to stand at room temperature under a nitrogen atmosphere forthree hours. By the end of this period the reaction mixture had startedto thicken. The mixture was then placed in a steel bomb. 85 ml. (8.5 g.,1.43 mol) of ethylene sulfide were then changed into the reaction systemand the system was allowed to stand at room temperature under a nitrogenatmosphere overnight. The resulting white polymer was dried overnight ina vacuum oven at 1 mm. Hg to remove the solvent and unreacted monomericmaterials. 91 g. (91% yield) of a white powdery copolymer were obtainedwhich had a melting point of 190-197 C. and an average melt index at 215C. of 0.4 g./min.

Example 16 An ethylene sulfide/propylene sulfide copolymer havingapproximately an 85/ 15 weight ratio of ethylene sulfide to propylenesulfide units was prepared as follows:

A clean 30-ounce bottle was flushed with nitrogen and successivelycharged with 100 ml. of methylene chloride, 0.15 ml. (0.0083 mol) ofoxygen-free water and 10.90 ml. (0.0115 rnol) of :1 0.001055 moi/ml.solution of diethyl zinc in benzene. The solution was allowed to standat room temperature under nitrogen until a yellow color developed. 15mi. (14.2 g., 0.192 mol) of propylene sulfide were then added to thesolution and the system was allowed to stand at room temperature undernitrogen until the solution began to thicken, which took about 3 hours.The mixture was then placed in a steel bomb. 85 ml. (8.5 g., 1.43 mol)of ethylene sulfide were then charged into the reaction system and thesystem was allowed to stand under nitrogen at room temperatureovernight. The resulting polymeric mass was dried overnight in a vacuumoven at 1 mm. Hg to remove the solvent and unreacted monomericmaterials. 90 g. (90% yield) of a white powdery copolymer were obtainedwhich had a melting point of 190205 C. and an average melt index at 215C. of 0.5 g./min.

Example 17 An ethylene sulfide/ propylene sulfide copolymer havingapproximately a 100/5 weight ratio of ethylene sulfide to propylenesulfide units was prepared as follows:

A steel bomb was flushed with nitrogen and charged successively with 50ml. of benzene, 0.042 ml. of oxygenfree water, ml. of propylene sulfidewhich had been fully distilled from calcium hydride and 2.2 ml. (2.3mmoles) of diethyl zinc. The reaction mixture was swirled under anitrogen atmosphere. A total of 100 ml. of freshly distilled ethylenesulfide was added to the reaction mixture in increments over a period ofapproximately hour.

The reaction system was allowed to stand at room temperature under anatmosphere of nitrogen overnight. The solid reaction product was driedovernight in a vacuum oven at 50 C./1 mm. Hg to yield 103 g. (98% yield)of a white powder having a melting range of 195200 C. and an averagemelt index at 215 C. of 0.6 g./min.

Example 18 An ethylene sulfide/propylene sulfide copolymer havingapproximately at 95/5 weight ratio composition was prepared as follows:

A steel bomb was flushed with nitrogen and charged successively with amixture of 95 ml. of freshly distilled ethylene sulfide and 5 ml. offreshly distilled propylene sulfide, 400 ml. of heptane, and 20 ml. of acatalyst solution. The catalyst solution was prepared by reacting 21.2millimoles of diethyl zinc and 0.40 ml. of oxygenfree water in 200 ml.of tetrahydrofuran. The reaction mixture was heated to C. and allowed toremain at this temperature in an atmosphere of nitrogen for two hours.The resulting copolymer was recovered by drying the solid reactionproduct overnight in a vacuum oven at 50 C./1 mm. Hg. 94 g. (94% yield)of a white powdery product were obtained, having a melting range ofl65198 C. and an average melt index at 215 C. of 0.7 g./min.

Example 19 A terpolymer having approximately an 10/5 weight ratio ofethylene sulfide/propylene sulfide/butylene sulfide units was preparedas follows:

A steel bomb was flushed with nitrogen and charged successively with amixture of 85 ml. of freshly distilled ethylene sulfide, 10 ml. offreshly distilled propylene sulfide and 5 ml. of freshly distilledbutylene sulfide, 400 ml. of heptane, and 20 ml. of a catalyst solution.The catalyst solution was prepared by reacting 11.1 milllmoles ofdiethyl zinc and 0.20 ml. of oxygen-free water in 100 ml. oftetrahydrofuran. The reaction mixture was heated to 80 C. and allowed toremain at this temperature in an atmosphere of nitrogen for two hours.The resulting terpolymer was recovered by drying the solid reactionproduct overnight in a vacuum oven at 50 C./ 1 mm. Hg. 100 g. (100%yield) of a white powdery product were obtained, having a melting rangeof 187-195 C. and an average melt index at 215 C. of 1.2 g./min.

Example 20 A copolymer having approximately a /10 weight ratio ofethylene sulfide to propylene sulfide units was prepared as follows:

A steel bomb was flushed With nitrogen and charged successively with amixture of 90 ml. of freshly distilled ethylene sulfide and 10 ml. offreshly distilled propylene sulfide, 400 ml. of heptane, and 20 ml. of acatalyst solution. The catalyst colution was prepared by reacting 21.2millimoles of diethyl zinc and 0.40 ml. of oxygenfree water in 200 ml.of tetrahydrofuran. The reaction mixture was heated to 80 C. and allowedto remain at this temperature in an atmosphere of nitrogen for twohours. The resulting copolymer was recovered by drying the solidreaction product overnight in a vacuum oven at 50 C./1 mm. Hg. 94 g.(94% yield) of a white powdery product were obtained, having a meltingrange of 170-203 C. and an average melt index at 215 C. of 0.6 g./min.

Example 21 A copolymer having approximately a 75/25 weight ratio ofethylene sulfide to propylene sulfide units was prepared as follows:

A steel bomb was flushed with nitrogen and charged successively with amixture of 75 ml. of freshly distilled ethylene sulfide and 25 ml. offreshly distilled propylene sulfide, 400 ml. of heptane, and 20 ml. of acatalyst solution. The catalyst solution was prepared by reacting 21.2millimoles of diethyl zinc and 0.40 ml. of oxygen-free Water in 200 ml.of tetrahydrofuran. The reaction mixture was heated to 80 C. and allowedto remain at this temperature in an atmosphere of nitrogen for twohours. The resulting copolymer was recovered by drying the solidreaction product overnight in a vacum oven at 50 C./l mm. Hg. 97 g. (97%yield) of a white powdery product were obtained, having a melting rangeof l75190 C. and an average melt index at 215 C. of 1.2 g./min.

Example 22 A copolymer having approximately a /5 weight ratio ofethylene sulfide to cyclohexene sulfide units was prepared as follows:

A steel bomb was flushed with nitrogen and charged successively with amixture of 95 ml. of freshly distilled ethylene sulfide and 5 g. offreshly distilled cyclohexene sulfide, 400 ml. of heptane, and 20 m1. ofa catalyst solu- 13 tion. The catalyst was prepared by reacting 21.2millimoles of diethyl zinc and 0.35 ml. of oxygen-free water in 200 ml.of tetrahydrofuran. The reaction mixture was heated to 80 C. and allowedto remain at this temperature in an atmosphere of nitrogen for twohours. The resulting copolymer was recovered by drying the solidreaction product overnight in a vacuum oven at 50 C./1 mm. Hg. 93 g.(93% yield) of a white powdery product were obtained, having a meltingrange of 202-205 C. and an average melt index at 215 C. of 1.1 g./min.

Example 23 A copolymer having approximately a 98/2 weight ratio ofethylene sulfide to propylene sulfide units was prepared as follows:

A steel bomb was fiushed with nitrogen and charged successively with amixture of 98 ml. of freshly distilled ethylene sulfide and 2 ml. offreshly distilled propylene sulfide, 400 ml. of heptane, and 20 ml. of acatalyst so lution. The catalyst was prepared by reacting 11.1millimoles of diethyl zinc and 0.20 ml. of oxygen-free water in 100 ml.of tetrahydrofuran. The reaction mixture was heated to 80 C. and allowedto remain at this temperature in an atmosphere of nitrogen for twohours. The resulting copolymer was recovered by drying the solidreaction product overnight in a vacuum oven at 50 C./1 mm. Hg. 96 g.(96% yield) of a white powdery product were obtained, having a meltingrange of 201203 C. and an average melt index at 215 C. of 0.4 g./min.

Example 24 A terpolymer having approximately an 80/10/10 weight ratio ofethylene sulfide/propylene sulfide/butylene sulfide units was preparedas follows:

A steel bomb was flushed with nitrogen and charged successively with amixture of 80 ml. of freshly distilled ethylene sulfide, 10 ml. offreshly distilled propylene sulfide, and 10 ml. of freshly distilledbutylene sulfide, 400 ml. of heptane, and 20 ml. of a catalyst solution.The catalyst was prepared by reacting 11.1 millimoles of diethyl zincand 0.20 ml. of oxygen-free water in 100 ml. of tetrahydrofuran. Thereaction mixture was heated to 80 C. and allowed to remain at thistemperature in an atmosphere of nitrogen for two hours. The resultingterpolymer was recovered by drying the solid reaction product overnightin a vacuum oven at 50 C. 1 mm. Hg. 96 g. (96% yield) of a white powderyproduct were obtained, having a melting range of 185190 C. and anaverage melt index at 215 C. of 1.0 g./min.

Example 25 A copolymer having approximately a 95/5 weight ratio ofethylene sulfide to butylene sulfide units was prepared as follows:

A steel bomb was flushed with nitrogen and charged successively with amixture of 95 ml. of freshly distilled ethylene sulfide and 5 g. offreshly distilled butylene sulfide, 400 ml. of heptane, and 20 ml. of acatalyst solution. The catalyst was prepared by reacting 21.2 millimolesof diethyl zinc and 0.35 ml. of oxygen-free water in 200 ml. oftetrahydrofuran. The reaction mixture was heated to 80 C. and allowed toremain at this temperature in an atmosphere of nitrogen for two hours.The resulting copolymer was recovered by drying the solid reactionproduct overnight in a vacuum oven at 50 C./1 mm. Hg. 98 g. (98% yield)of a white powdery product were obtained, having a melting range of199203 C. and an average melt index at 215 C. of 0.3 g./min.

Example 26 A copolymer having approximately a 95 5 weight ratio ofethylene sulfide to allylthioglycidyl ether units was prepared asfollows:

A steel bomb was flushed with nitrogen and charged successively with amixture of 95 ml. of freshly distilled ethylene sulfide and 5 g. offreshly distilled allylthioglycidyl ether, 400 ml. of heptane, and 20ml. of a catalyst solution. The catalyst was prepared by reacting 11.1millimoles of diethyl zinc and 0.20 ml. of oxygenfree water in 100 ml.of tetrahydrofuran. The reaction mixture was heated to C. and allowed toremain at this temperature for two hours. The resulting copolymer wasrecovered by drying the solid reaction product overnight in a vacuumoven at 50 C./1 mm. Hg. 98 g. (98% yield) of product were obtained,having a melting range of 200-205 C. and an average melt index at 215 C.of 0.1 g./min.

Example 27 This example illustrates the difference in molding propertiesbetween a first polymer (Polymer A) made according to the presentinvention and a second polymer (Polymer B) made according to a prior artprocess for making ethylene sulfide homopolymers, i.e., that describedin an article by Boileau et al, entitled, MacromolecularChemistryPolymers of Ethylene Sulfide and Propylene Sulfide, publishedin Compte Rendus 252, 882 (1961).

Polymer A was made as follows: The polymerization was carried out infive 30 oz. glass polymerization bottles. Each glass bottle wassequentially charged with 400 ml. of dried benzene, 100 ml. of driedethylene sulfide monomer, 0.0011 mole (0.02 ml.) of water and 1 ml. of abenzene solution containing 0.0011 mole of diethyl zinc. The chargingwas carried out under nitrogen and the bottles were capped. The bottleswere placed in a polymerization bath set at 80 C. for 2 hours, withagitation. The wet white polymer thus obtained was dried in an oven at50 C. under vacuum for about 24 hours. The melting point of this polymerranged from 20'5207 C. When 4 gms. of this polymer were tested for meltindex at 215 C., the melt index of the polymer was found to be 0.274gm./min.

Polymer B was made as follows: A 3-neck 3 liter flask equipped with astirrer was charged with 1250 ml. of a 3.5% aqueous sodium hydroxidesolution having a pH of 11.8. As the catalyst solution was beingstirred, 500 ml. of ethylene sulfide was added thereto dropwise. Withina short period of time a polymer was seen to be formed. A slightexotherm developed, and the flask was cooled externally. This reactionmixture was allowed to stand overnight with continuous stirring. Thenext day the polymer product was filtered and washed to yield 485 gms.of a fine white powder. The polymer had a melting point of 193-194 C.When 4 gms. of this material was tested for melt index at 215 C., theentire sample flowed out of the test instrument in less than 1 minute.This indicates that the polymer had a melt index o more than 4 gms./min.at 215 C.

MOLDING PROCEDURE The polymers were molded using a hydraulicallyoperated ram jet injection molding machine (Hinchman Mfg. Co., Inc.,Roselle, N.J.), injecting into a 4-inch long tensile bar mold. SincePolymer A was rather fluffy, it was difficult to feed to the processingmachinery, and accordingly, was compacted into 4-inch discs which werebroken into chips for ease of loading. Polymer B fed easily and wastherefore used without compacting.

During molding the cylinder temperature was maintained at 177-205 C. Themold was pre-heated to 125 C. before use, and cooled during use to C.The injection pressure was 1100 p.s.i. The molding cycle included a 510second dwell time of the polymer in the cylinder, and a cooling time ofup to 30 seconds.

The tensile bar molded from Polymer A was removed from the mold andtested in a standard tensile tester with the following results:

Tensile strength p.s.i 4000 Elongation at break percent 1.43 Tensilemodulus p.s.i 283,000

The bar molded from Polymer B could not be tested at all. Upon openingthe mold it was found that the bar had broken into several pieces. Thematerial was so brittle that no tensile test could be performed thereon.

The foregoing test results show that an ethylene sulfide polymer of thetype disclosed in the Boileau et al. article is incapable of beingmolded to produce a molded article having acceptable physicalproperties, whereas the polymers claimed in this application yielduseful moldings.

Example 28 A copolymer having approximately a 80/20 weight ratio ofethylene sulfide to butylene sulfide units Was prepared as follows:

A steel bomb was flushed with nitrogen and charged successively with amixture of 80 ml. of freshly distilled ethylene sulfide and 20 g. offreshly distilled butylene sulfide, 400 ml. of heptane, and 20 ml. of acatalyst solution. The catalyst solution was prepared by reacting 21.2millimoles of diethyl zinc and 0.35 ml. of oxygen-free water in 200 ml.of tetrahydrofuran. The reaction mixture was heated to 80 C. and allowedto remain at this temperature in an atmosphere of nitrogen for twohours. The resulting copolymer was recovered by drying the solidreaction product overnight in a vacuum oven at 50 C./1 mm. Hg. 99 g.(99% yield) of a white powdery product were obtained, having a meltingrange of 199-203 C. and an average melt index at 215 C. of 1.3 g./min.

Example 29 A copolymer having approximately a 70/30 weight ratio ofethylene sulfide to propylene sulfide units was prepared as follows:

A steel bomb was fiushed with nitrogen and charged successively with amixture of 70 ml. of freshly distilled ethylene sulfide and 30 ml. offreshly distilled propylene sulfide, 400 ml. of heptane, and 20 ml.(2.22 millimoles) of a catalyst solution consisting of 10.5 ml. ofdiethyl zinc, 0.20 ml. of oxygen-free water, and 100 ml. oftetrahydrofuran. The reaction mixture was heated to 80 C. and allowed toremain at this temperature in an atmosphere of nitrogen for two hours.The resulting copolymer was recovered by drying the solid reactionproduct overnight in a vacuum oven at 50 C./1 mm. Hg. 94 g. (94% yield)of product were obtained, having a melting point of 165-175 C. and anaverage melt index at 215 C. of 1.5 g./min.

Example 30 A dry 30 oz. glass polymerization vessel was sequentiallycharged with mixing under a blanket of nitrogen gas with 400 ml. ofdried benzene, approximately 100 g. (100 ml.) of dried ethylene sulfidemonomer, 0.0011 mole (0.02 ml.) of water and 0.74 ml. of a benzenesolution containing 0.0011 moles of diethyl zinc. The vessel was sealedand the contents raised to and maintained at 80 C. for 2 hours withagitation. The wet white polymer thus obtained was dried at 2100 mm. Hgvacuum in an oven at 60-70 C. for about 24 hours to produce 70 g. of adried white powdery crystalline polymer product having a melting pointof 204208 C.

When tested as in ASTM D-621 using a 2000 p.s.i. load for 24 hours at122 F., a four ply laminate of molded polymer in the form of /2" cubesexhibited a deformation under load of 0.26%.

When tested as in ASTM D-570 (24 hours at 73 F.) Ms x /2 x 5" moldedsamples of the polymer exhibited a water absorption value of 0.01%.

When tested as in ASTM D-648 (264 p.s.i. load) 44" x /2 x 5" moldedsamples of the polymer exhibited a heat distortion temperature of 303 F.

It is of course to be understood that the foregoing examples areintended to be illustrative only and that numerous changes can be madein the ingredients, proportions and conditions specifically disclosedtherein. For example, minor amounts of monomers other than the vicinalepisulfides mentioned above can be incorporated in the backbone of thepolymeric materials of the present invention to produce interpolymershaving positive melt index values below about 1.5 grams/minute at 215 C.Minor amount in this context is intended to mean an amount of thenon-vicinal episulfide monomer sufficiently small that it neitherproduces any significantly adverse effect on the molding properties ofthe resulting interpolymer nor increases the melt index of theinterpolymer above about 1.5. Among the other monomers that can be soused are cyclic sulfides having the structure:

R1 Ml in which n=3 to 6, and R and R may be hydrogen, a branched orlinear alkyl group having from 1 to 10 carbon atoms, an aryl, anarylalkyl and/or an alkylaryl group. R and R may also be heterocyclic,alicyclic, bicyclic or polycyclic. Examples of such cyclic sulfides aretrimethylene sulfide, pentamethylene sulfide and hexamethylene sulfide.

Also minor amounts of units derived from various ethylenicallyunsaturated monomers may be incorporated in the present polymers. Suchunsaturated monomers include olefins, such as ethylene, propylene,butylene and isobutylene; conjugated and non-conjugated dienes, such asbutadiene, isoprene and 1,4 pentadiene; and vinyl com.- pounds, such asstyrene, vinyl acetate, ethyl acrylate, methyl acrylate, methylmethacrylate, butyl acrylate, acrylonitrile, vinyl isobutyl ether,methyl styrene, hydroxy propyl methacrylate, tetrafiuoroethylene,chlorotrifluoroethylene and hexafluoropropylene. Still other compoundsthat may be used in minor amount have the structure:

in which X is oxygen or nitrogen and R and R may be hydrogen, a branchedor linear alkyl group having from 1 to 10 carbon atoms, an aryl, anaralkyl and/ or an alkylaryl group. R and R may also be heterocyclic,alicyclic, bicyclic or polycyclic. Examples of such compounds arestyrene oxide, ethylene oxide, propylene oxide, 1,2-butylene oxide,2,3-butylene oxide, ethylene imine and propylene imine. Still othercompounds that may be used in minor amount are formaldehyde, trioxane,hydroxyisobutyric acid, tetrahydrofuran, 1,3-dioxolane 1,4-dioxane,trimethylene oxide, tetramethylene oxide and pentamethylene oxide.

Other modifications within the scope of the invention will be apparentto those skilled in the art.

We claim:

1. A solid, high molecular weight, moldable, predominately crystalline,essentially homopolymeric poly(ethylene sulfide) having a positive meltindex value at 215 C. below about 1.5 grams per minute.

2. A solid, high molecular weight, moldable, predominately crystalline,essentially homopolymeric poly(ethylene sulfide) having a positive meltindex value at 215 C. below about 0.7 gram per minute.

3. A solid, high molecular weight, moldable, predominately crystalline,essentially homopolymeric poly(ethylene sulfide) having a melting pointbetween 200 and 215 C. and a positive melt index value at 215 C. below1.5 grams per minute.

4. A solid, high molecular weight, moldable, predominately crystalline,essentially homopolymeric poly(ethylene sulfide) substantially insolublein o-dichlorobenzene at 180 C. and having a positive melt index value at215 C. below 1.5 grams per minute.

5. A solid, high molecular weight, moldable predominately crystalline,essentially homopolymeric poly(ethyl- 17 ene sulfide) substantiallyinsoluble in o-dichlorobenzene at 180 C. and having a melting point of200 to 215 C. and a positive melt index value at 215 C. below 1.5 gramsper minute.

6. A molded object molded under heat and pressure from the polymerdefined in claim 1.

7. A molded object molded under heat and pressure from the polymerdefined in claim 2.

8. A solid, high molecular weight, moldable polymer consistingessentially of ethylene sulfide units and from to 30% by weight of saidpolymer of units derived from at least one vicinal episulfide having 3to carbon atoms, said polymer having a positive melt index value at 215C. below about 1.5 grams per minute.

9. A solid, high molecular weight, moldable polymer having a positivemelt index value at 215 C. below about 1.5 grams per minute and selectedfrom the group consisting of homopolymers of ethylene sulfide andinterpolymers containing at least 70% by weight of ethylene sulfideunits and up to 30% by weight of units derived from at least one othervicinal episulfide monomer selected from the group consisting ofpropylene sulfide, 1,2-butylene sulfide, 2,3-butylene sulfide,isobutylene sulfide, cyclohexene sulfide, styrene sulfide, vinylcyclohexane sulfide, vinyl cyclo hexene sulfide, para-methyl styrenesulfide, butadiene monoepisulfide, butadiene diepisulfide, 2-benzylthiirane; 1,2-epoxy-3,4-epithiobutane and allylthioglycidyl ether.

10. An interpolymer according to claim 9 and wherein at least one ofsaid other vicinal episulfides is propylene sulfide.

11. A polymer according to claim 9 and wherein at least one of saidother vicinal episulfides is at least one of said butylene sulfides.

12. A polymer according to claim 9 and wherein said other vicinalepisulfides are propylene sulfide and at least one of said butylenesulfides.

13. A polymer according to claim 9 and wherein at least one of saidother vicinal episulfides is cyclohexene sulfide.

14. A polymer according to claim 9 and wherein at least one of saidother vicinal episulfides is allylthioglycidyl ether.

15. A solid, high molecular weight, moldable ethylene sulfide polymerhaving a positive melt index value at 215 C. below about 1.5 grams perminute.

16. A solid, high molecular weight, moldable ethylene sulfide polymerhaving a positive melt index value at 215 C. below about 1.5 grams perminute, a melting point of about 200 to 215 C. and being substantiallyinsoluble in o-dichlorobenzene at 180 C.

17. A solid, high molecular weight, moldable polymer having a positivemelt index value at 215 C. of up to about 1.5 grams per minute andformed from at least by Weight of ethylene sulfide and up to 30% byweight of at least one other vicinal episulfide monomer.

18. A solid, high molecular weight, moldable polymer having a positivemelt index value at 215 C. of up to about 1.5 grams per minute and atleast 70% by Weight of recurring -CH CH S units in its polymericbackbone.

19. A solid, high molecular weight, moldable polymer having a positivemelt index value of 215 C. of up to about 1.5 grams per minute and a.major portion by weight of recurring -CH CH -S- units in its polymericbackbone.

20. A solid, high molecular weight, moldable polymer having a positivemelt index value at 215 C. of up to about 1.5 grams per minute andformed from at least a major amount of ethylene sulfide units.

21. A solid, high molecular weight, moldable polymer having a positivemelt index value at 215 C. of up to about 1.5 grams per minute andformed from at least 70% by Weight of ethylene sulfide units.

22. As a new article of manufacture, an article molded from an ethylenesulfide polymer having a melting point of at least about 200 C. and amelt index of less than about 1.5 grams per minute at 215 C.

23. As a new article of manufacture, an article molded from stabilizedethylene sulfide polymer, said polymer having a melting point of atleast about 200 C. and a melt index of less than about 1.5 grams perminute at 215 C.

24. An article as in claim 23 which is shaped in the form of a sheet.

25. An article as in claim 23 which is tubular in shape.

26. An article as in claim 23 which is funicular in shape.

References Cited UNITED STATES PATENTS 3,000,865 9/1961 Gurgiolo 260-793,222,326 12/1965 Brodoway 260-79.7 3,225,120 12/1965 Baker 2608743,300,454 1/1967 Osborn 26079.7

FOREIGN PATENTS 700,998 12/1964 Canada.

JOSEPH L. SCHOFER, Primary Examiner. D. K. DENENBERG, AssistantExaminer,

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,365,431 January 23 1968 Riad H. Gobran et al.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 1, line 37, for "detailed" read detail column 2, line 51, for"confronted" read conformed column 4, line 50, for "rescribed" readdescribed column 11, line 11, for "8.5" read 85.5 same line 11, for"changed" read charged line 36, for "8 .5" read 85.5 line 68, for "at"read a column 12, line 38, for "colution" read solution column 16, lines38 to 40, the formula should appear as shown below instead of as in thepatent:

R CH-CH-R S1gned and sealed this 8th day of April 1969 Attest:

EDWARD J. BRENNER Commissioner of Patents Edward M. Fletcher, Jr.

Attesting Officer

